Pump dredger or suction dredger



Jan. 13, 1925. v 1,523,071

T. IMAOKA rum mmpama on sun'non DREDGER Filed Nov. 6, 1922 2 Sheets-Sheet; J

7Zmez0 J 00 Jan. 13, 1925. 1,523,011

.. T. IMAOKA PUMP DRBDGER 0R SUCTION DREDGER 2 Sheets-Sheet 2 Filed Nov. 6, 1922 Patented Jan. 13, 1925.

' UNHTEB STATES earner ffirt t mh.

TGMEZO IMAO'KA, OF KITAKU, OSAKA CITY, JAPAN.

PUMP DREDGEE- OB, SUCTION DREDGER.

Application filed November To all whom it may concern:

Be it known that I, Torrnzo InAoKA, subject of the Emperor ofJapan, residing at No. 10, Naruomachi, Kitaku, Osaka City, Japan, have invented certain new and useful Improvements in Pump Dredgers or Suction Dredgers, of which the following is a specification.

This invention relates to improvements in pump dredger or suction dredger.

The pontoon has two rods to be stieked up the sea bottom during the dredging operation and pulled out alternately. One rod is positioned on the axial line of the pontoon and is called the central rod and another is situated on a line inclined to the axial line and is called the advancing rod.

The pontoon is turned in one and opposite direction about the central rod an d the advancing rod alternately performing dredging operation during its turning about the rods.

The object is to advance the pontoon along a straight line dredging a boundary having a definite width, by which a fixed delivery spout may be used instead of the flexible one necessary in the pump dredger hitherto used.

Fig. 1 is a side elevation of the dredger.

Fig. 2 is a top plan view of the dredge.

Fig. 3 is a geometrical figure to explain the action of dredger.

Fig. 4 is a diagram showing the positions and course of the pontoon in practical use.

The pontoon of pump dredger or suction dredger hitherto used can scarcely advance in a definite direction, consequently the boundary of the dredged area is very irregular. This invention is contrived to eliminate this defect and its essential feature is to advance the pontoon in a definite direction performing dredging operation, by which a straight boundary having a definite width can be dredged regularly and the delivery spout may be fixed in a desired position.

In the drawings a designates the pontoon and 7) the main pump. 0 is the suction pipe and (Z is the delivery pipe. The suction pipe has its bottom end connected pivotally in such a way that the inlet may be turned in a plane perpendicular to the axial line of the pontoon in accordance with the tide or the depth of the sea bottom to be dredged. By this construction the inlet of the se ti n 6, 1922. Serial No. 599,455.

pipe may be faced to the inclined surface to be dredged and the dredged trace marked by the turning movement of the pontoon will be a circular curve approximately.

The delivery pipe is provided with a turntable joint 6 in the straight line of the central rod 71 and is connected to the horizontal branch 9 by the vertical pipe 7". The mud or sand dredged is delivered to the spout 1' from the outlet of the delivery pipe it connected to the branch pipe 6/. z is the central rod situated on the axial line of the pontoon and this rod 2' is to be forced into the sea bottom during a dredging operation and the ponton is to be turned 90 about this rod 2'.

When the pontoon turns 90, one dredging operation is ended. Then. the advancing rod j is positioned on a line inclined 45 to the axial line, is forced into'the sea bottom, and the central rod 2' is pulled out and then the pontoon is to be turned 90 in the opposite direction about the advancing rod j performing the next dredging operation.

The distance the pontoon is to be ad vanced per dredging operation depends upon the nature of the mud or sand to be dredged and the distance may be adjusted by changing the relative positions of the advancing rod 7' to the central rod 2'. For this purpose, the beam is is provided along the line in clined 45 to the axial line and the ad.- vancing rod may change its position along the beam is.

The reason why the pontoon takes a defi- Ill lte course is illustrated geometrically in When the pontoon a is in the position shown by the full lines. the central rod is in the position shown by C, the inlet of the suction pipe at the point S and the out let of the delivery pipe at the point D.

If the pontoon is moved to the position shown by the dotted line turning 90 about the central rod at C, the inlet of the suction pipe will be moved to the point S.

At this time the central rod is pulled out and the advancing rod at the point B is inserted and then the pontoon is turned in opposite direction about the advancing rod at When it turns 90 the inlet of the suction pipe will be moved to the point S".

N extly the advancing rod is to be pulled out and the central rod at the point C is in sorted and the pontoon is turned about the central rod etc and so on. I

In the triangles CSR and CS"R GS' CS SR:SIt CR CR, therefore these triangles are similar and the angles SGR and SCR are similar.

As the angles RG'C and RCD are 45, LSCR+ LRCC= LSCR-l- ARCD: 180.

By the above reason, CC and SS are on a straight line, consequently it must be clear that the pontoon advances along a definite straight line.

ABis a distance. which the delivery end D moves on the right and left during the pontoon advances along the course CC.

CR CC' sin 45 0.70? CC. AB GR (1-sin 45):0207 CC.

Such small movement of the outlet ma'yi be made up by increasing a little the Width of the delivery spout 1 or by a flexible joint of the delivery pipe with the spout.

In the practical use of this dredger it is convenient to position the pontoon firstly on the position 0 shown in Fig. 4 and: to dredge the boundary having the Width 3?. When the pontoon completes a desired course, it is to be moved to the position 9, the opposite side of the delivery spout '1 and repeat the dredging operation.

The final operation is the moving of the pontoon to the position 3 and the dredging of the mud or sand laying under the spout 0".

Thus a Wide boundary may be dredged,

fixing the delivery spout in a desired position.

Having noW particularly described and ascertained the nature of my said invention, and in What manner the same is to be pertormed, Ideclare that What I claim is- The combination with a pump dredge, of means whereby said dredge may be advanced along .a straight line Whereby a dredging operation of uniform Width may take place, said means comprising a vertically disposed member slidably mounted in an opening of the dredge adjacent one end thereof and in the plane of the longitudinal axis'of the dredge and adapted to be imbedded in the bottom of a body of Water, a

second vertically disposed member, said sec ond member being adapted to be received in any of a plurality of apertures disposed at right angles to each other and having their center apertures positioned for the reception of the'first mentioned vertically disposed member, said crossed plurality of apertures being equidistant from the aperture in which the first mentioned member is disposed andequidistant from the longitudinal axis of the dredge. I

In testimony whereof I afiix my signature in presence of two Witnesses. 

